The invention relates to a method of storing user information items on a record carrier for subsequent presentation to a user, and to a record carrier whereon information items have been stored by such a method.
The invention further relates to an apparatus for reproducing user information items stored on such a record carrier, the apparatus including means for reading and reproducing user information items from specified locations on the record carrier and control means for reading control information from the record carrier and for specifying to the reproducing means the locations of user information items to be reproduced.
One known apparatus of the above type is the compact disc (CD) player for reproducing items of audio information, where the control information comprises a "table of contents" of stored items. In particular, however, a recording CD player is described in EP-O 346 979 A2 (PHQ88018) in which control information stored on the disc includes a list of track numbers defining a user's preferred reproduction sequence for the recorded items. The apparatus is then controlled by a simple microcontroller to reproduce the items in accordance with the stored list, notwithstanding that the items are stored in a different order within the continuous time sequence defined by the spiral track on the record carrier (CD).
A low cost apparatus which can reproduce images as well as sounds from a CD is the forthcoming Photo CD player, described in various papers at the IEEE International Conference on Consumer Electronics 1991, see ICCE '91 Digest of Technical Papers, pages 315-323.
There are also today several so-called multimedia computer-based systems which can reproduce images, sounds and text from CD record carriers, including in particular the Compact Disc-Interactive system (CD-I). A CD-I player is commercially available from Philips Consumer Electronics in Knoxville, Tenn. These multimedia systems include powerful microprocessors and specialised peripheral circuits, running under control of a real-time operating system and application programs loaded from the disc, and can implement many styles of user interaction, including multi-level menus and the like, to provide rapid access to the large amount of information stored on the disc. CD-I and other fully-featured multimedia systems are inevitably more expensive both in the cost of the consumer apparatus and the effort involved in organising and storing information on the record carriers.
Such a level of interactivity cannot be provided in low-cost systems such as Photo CD and audio CD, chiefly because the control means is limited typically to an 8-bit microcontroller running a small predetermined control program stored in read-only memory (ROM). Such a microcontroller cannot generally accept new programs from the record carrier, and cannot process data read from the disc at the full CD data rate.